[Patent document 1] JP 2009-274514 A (US 2009/0287370 A1)
There is known a technology to store a vehicle identification code in a specific one of several in-vehicle electronic control units mounted in a vehicle and enables an identification of the vehicle by referring to the vehicle identification code stored in the specific electronic control unit. Such an identification code or number is practically used in the U.S.A. as VIN (Vehicle Identification Number) that is given to each vehicle.
One example of a vehicle provided with the above technology is as follows. In a vehicle inspection, a dedicated scanning tool is connected to an in-vehicle network of the vehicle; the vehicle identification number is acquired from the electronic control unit via the in-vehicle network, thereby enabling the identification of the vehicle that is inspected. In such a vehicle inspection, for instance, failure diagnosis related information is acquired from an in-vehicle electronic control unit so as to check for an anomaly. Here, the stored failure diagnosis related information indicates an execution or a non-execution and an execution result of a failure diagnosis.
In addition, the above electronic control unit storing a VIN (referred to as a VIN storage ECU) is known which is enabled to rewrite the VIN stored therein. The VIN that is stored in the VIN storage ECU is assigned uniquely to each vehicle. When the VIN storage ECU is replaced due to a defect, there is a need to write the same unique VIN in a new electronic control unit to serve as a VIN storage ECU. For such a need, the rewriting function of the VIN is thus used.
However, when the rewriting function is provided to the VIN storage ECU, it might be abused. For example, suppose a case where (i) a VIN storage ECU of a vehicle B having no anomaly is mounted in a vehicle A having an anomaly, and (ii) the VIN of the VIN storage ECU is rewritten to the VIN unique to the vehicle A. Here, the failure diagnosis related information stored in the VIN storage ECU, that is belonging to the vehicle B having no anomaly can be pretended to be pertinent to the vehicle A, This may be used as a tool for letting the vehicle A pass the inspection (e.g., emission test) unjustly.
Therefore, according to the regulation (CARB OBD2) in the U.S.A., the rewriting of a VIN is required to be accompanied by simultaneously eliminating the emission-related failure diagnosis information. In response to such a requirement, there is considered a system to eliminate the failure diagnosis prior to the rewriting of a VIN (refer to Patent document 1).
In this regard, the above technology to eliminate the failure diagnosis related information prior to the rewriting of the VIN tends to need a complicated procedure.